A compact Class E rectifier for megahertz wireless power transfer

It is promising for consumer electronics to achieve the long wireless charging distance by increasing the system frequency to megahertz. For MHz systems, hard-switching-based rectifiers(e.g., the full-bridge rectifier) will have significant switching loss. Therefore, it is attractive to apply the soft-switching techniques for MHz rectifiers. The Class E rectifier is a proper candidate for MHz system due to its soft-switching topology. This paper presents a compact Class E rectifier for megahertz wireless power transfer. The equivalent circuit model and simulation are presented to analyze behavior of the proposed rectifier. Finally, a 6.78 MHz Class E rectifier is implemented and experiment results show that proposed system can achieve a 92% efficiency with an input power of 10 W.